Photoacoustic imaging (PAI) is a novel medical imaging technology. As a non-invasive and non-ionizing imaging technology

PAI features high resolution

high contrast and high penetration depth. In order to produce a significant photoacoustic signal in the diagnosis of tissue

this imaging technique requires to append contrast agent for interacting with tissues. However

the lack of appropriate contrast agents limits the current application of PAI in the biomedical field. Conjugated polymers are widely utilized for PAI due to their hallmarks of excellent optical performance and good compatibility. Herein

we review the application of conjugated polymers as exogenous contrast agents in PAI and the development of conjugated polymers for contrast agents is prospected.